It sounds quite nasty. I'm wondering if the other boys exaggerated your son's response, to make these parents think he is dangerous. Sounds like the kind of thing bullies will do. Maybe you could find out if other parents have had trouble with these boys as well, without aggravating the situation more? I'm sorry I can't be more helpful, my only advice is don't get into some awful argument with them if possible, and try to keep your dignity. Good luck.
Ginny
3bNii
17/19/BSL
Hair dark brown getting greys, has been coloured and bleached. Now just using henna, but still have old colour and damage to get rid of.
CO with Prairie Naturals Indian Summer conditioner, plus whatever leftovers I'm using up.
ACV rinse.
Leave in oils jojoba, coconut, avocado.